WORLD POPULATION 109
declined significantly. The developing nations in Asia, Latin America, and Africa, with their 20th century death rates and medieval birth rates, are perpetuating the second world population explosion.
Although the first and second population explosions have affected, or are affecting, every corner of the globe, the majority of the world's peoples live in seven giant nations. In mid-1968, the seven largest nations in the world contained about three fifths of the world's peoples, some 2 billion. These nations were mainland China, with perhaps 730 million inhabitants; India, with about 525 million; the Soviet Union with 240 million; the United States with 200 million; Pakistan with 125 million; Indonesia with over 110 million; and Japan with about 100 million. These nations share a major responsibility for the population outlook of the world.
Population Growth, 1920 to 1960
An analysis of developments between 1920 and 1960 by the United Nations provides a framework for considering the population prospect for the world and for significant regional and national groupings (10, pp. 13, 133). In those 40 years, world population increased from 1.9 to 3 billion, or by 60 percerrt/rhere was a great difference, however^ in the growth rates of world regions grouped by level of economic development, the less developed regions of the world (Africa, Latin America, east Asia, and south Asia) increased from 1.3 to 2.1 billion, or about 70 percent. In contrast, the more developed areas (northern America, Europe, the Soviet Union, and Oceania) increased by only 40 percent.
Regions of the world are classed as "less developed" or "developed" on an economic basis. An analysis of population characteristics reveals that differences in the level of human reproductivity sharply distinguish the developed from the less developed areas.
About two thirds of the less developed countries have birth rates ranging from 40 to 50 (births per 1,000 persons per year); whereas two thirds of the more developed areas have birth rates of 17 to 23. There is also a difference between the less developed and the developed countries in death rates. It is not as marked as the difference in birth rates, however, because of the great decline in mortality since the end of World War II. Expectation of life at birth in most of the less developed countries ranges from 30 to 60 years, whereas in most of the developed nations it ranges from about 67 to 72 years. With present trends in public health and other lifesaving programs, the differences in mortality will no doubt diminish further.
Despite the differences between developed and less developed nations in fertility and mortality, there is overlap between them in rates of population